1. Field of the Invention
The invention relates to image processing apparatus and method for performing a color process.
2. Related Background Art
Generally, in an image processing apparatus such as a color copying machine or the like, it is desirable that a color reproducibility, a gradation, and the like of a hard copy output image are reconstructed at a high fidelity as much as possible for an original image.
Hitherto, by performing a gamma conversion and a masking process to an inputted color signal, the input color signal is reconstructed onto a recording medium at a high fidelity as much as possible by using a recording agent such as a toner or the like.
In the copying machine, there is used a technique that is peculiar to the copying machine such as a same background color level control or the like which is executed to a plurality of color components in order to obtain a desired output image of the user.
Such an image processing apparatus as mentioned above has the following problems.
In the above image processing apparatus, an image is merely reconstructed at a high fidelity for an input color signal and the color expressed by the input signal is not reconstructed at a high fidelity.
Namely, a consideration is made only for the inside of a color reconstructing range which can be reconstructed by the image processing apparatus. No consideration is made for a signal out of the color reconstructing range, so that a gradation of the signal out of the color reconstructing range is deteriorated or a color tone of such a signal changes or the like. There is, consequently, a problem such that the color tone of the original cannot be reconstructed at a high fidelity.
On the other hand, since the same background color level control is executed to a plurality of color components, there is a problem such that the background color level control in which the color tone of a highlight portion is preserved cannot be performed.